Jack-screw.



No. 655,297. Patented Aug. 7, |900. y w. o. DERBY.

JACK SCREW.

(Application led Jan. 18, 1898. Renewed Jung 29, 1900.)

(Np Model.)

UNITED' STATES PATENT OEEIcE.I t,

wILLIs o. DERBY, on SAGANING, MICHIGAN.

JACK-SCREW.

STE*'EGIFIG'ATIONY forming part of Letters Patent o.` 655,297, dated August '7, 1900. Application led January 18, 1998. Renewed Ji'une 29, 1900, V Serial No. V22,1).92. (No model.)

To @ZZ whom t may concern: l

Be it known that LWILLIs O..DERRY, a citizen of the United States, residing at Saganing,in the county of Arenac and State of Michigan, have invented a new and useful .Tack- Screw, of which the following is a specification. A

The invention relates to improvements in j ack-screws. Y

The object of the present invention is to improve the construction of jack-screws and to provide a simple and efficient one which will possess great strength and durability and which will be capable of easy adjustment.

The invention consists in the construction and novel combination and arrangement of parts, as hereinafter fully described, illustrated in the accompanying drawings, and pointed out in the claims hereto appended.

In the drawings, Figure 1 is a perspective viewofajack-screw constructedin accordance with this invention. Fig. 2 is a vertical sectional view of the same. Fig. 3 is a horizontal sectional view, the antifriction-rollers being shown in plan view. Fig. el is a detail perspective view of the nut, illustrating the arrangement of its teeth, which mesh with the pinion.

Like numerals of reference designate corresponding parts in all the figures of the drawings.

1 designates a vertically-adjustable screw provided at its upper end with a head 2 andV arranged within a hollow standard 3,provided with a central longitudinal opening to receive the screw and having grooves 4 at opposite sides thereof adapted 4to be engaged by the terminals of a transverse pin 5, whereby the screw is held against rotation. The pin 5 passes through a slot of the lower end of the screw, and the bottom portion ot' the standard is slotted at 6 to facilitate the introduction of the pin into the slot of the screw. The longitudinal grooves 4 terminate short of the up per end of 'the standard, and the transverse pin 5 serves as a stop to prevent the screw from being entirely withdrawn from the stand- 'ard by the action of a nut 7.

The upper end of the standard, which has a suitable handle, is provided with an annular groove 7F and has bearing notches or recesses 8 at the inner and outer walls thereof for the reception of journals 9 of antifrictionrolls'lO, arranged` in the annular groove 7'it and interposed between the standard and the nut. The lower., face of the nut? is conical, and the antifricticn-rolls 10 are tapering and present inwardly-inclined faces which conform to the configuration of the lower face of the nut, as clearly illustrated in Fig. 2 of the accompanying drawings.

The annular series of antifriction-rolls enables the nut to rotate frictionlessly, and the said nut is provided at its lower face with an annular series of depending teeth l1, located outside of the annular series of antifrictionrolls and meshing with a pinion 12, which is mounted on a journal 13 of one of the series of antifriction-rolls. One of the journals ot the antifriction-rolls is extended outward to form a shaft for the receptio-nof the pinion 12, and a crank-handle 14 is fixed or other'- wise connected with the extended journal 13 to enable the gearing to be operated. The gearing may be increased, if desired, so that a very large and heavy screw may be easily operated by only a slight exertion on the part of the operator.

When the device is carried in a horizontal position, the nut and the screw are held against outward movement by a catch 16, se-

cured to the outer face of the standard at a point diametrically opposite the pinion, and v autifriction-rolls, and it retains their journals in the bearing-recesses.

The inventiony has the following advantages: The jack-screw is simple and comparatively inexpensive in construction, and it is adapted to be quickly adjusted to raise and lower the screw. The antifriction-rollers, which are interposed between the standard and the nut, reduce the friction to arninimum, and the catch prevents the nut from getting out of mesh with the pinion.

Changes in the form, proportion, and minor details of construction may be resorted t0 IOO . Without departing from the spirit or sacrificing any of the advantages of this invention. What I claim is- -1. In a device of the class described, the combination ofa standard provided at its upper end with an annular groove, and having bearing-recessesat the inner and outer Walls thereof, a series of antifriction-rolls arranged in said groove and provided at their inner and outer ends with journals fitting in the bearing-recesses, the journal of one of the rolls being extended at the outer end thereof, a gearwheel mounted on the cxtended journal, avertically-adjustable screw, i a nut engaging the screW'and resting upon A y the antifricton-rolls, said nut being provided with teeth meshing with the gear-Wheel, and means for rotating the latter, substantially as described.

2. In a device of the class described, the combination of a standard provided at its upper end with an annular groove and having bearing-recesses at the inner and outer walls thereof, a series of antifriction-rolls 'arranged in said grooveand provided atL their inner and outer ends with journals fitting in f the bearing-recesses, a vertically-'adjustable J screw, a\ rotary nutarranged on the antifric-Y f tion-rolls and engaging the screw, said nut being provided with an exterior annular groove, means for rotating the nut, and a catch constructed of resilient materiahmount# f l ed on the standard and provided at its top with an inwardly-extending arm engaging the groove of the nut, said catch being adapted to hold the nut and the screw against outv ward movement whenthe device lis carried f in a horizontal posi-tion, and capable of being drawn outward to disengage its arm from the groove of the nut, substantially as and for the purpose described.

In .testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

WILLIS O, BERRY.

Witnesses:

H. A. CHAMBERLMN, E. C. BULLER. 

